Presbyopia (eyestrain)

What is presbyopia?

Presbyopia or eyestrain is the loss of accommodation – of focusing power – of the crystalline lens.

The eye focuses images with the help of two lenses: the cornea and the crystalline lens. The cornea is a fixed lens that cannot vary in shape or size. The crystalline lens, on the other hand, is a lens that is attached to a muscle that allows us to vary its shape and, therefore, its power. Thanks to these movements, we can focus both near and far images. From the age of 45, the crystalline lens hardens and loses elasticity. The consequence is that the muscle responsible for changing its shape (ciliary muscle) is unable to do so and the ability to focus – or accommodate – is lost.

The more distant the images are, the more relaxed the ciliary muscle is, but the closer we get to an object, the more the muscle tightens in order to focus. This is why when the muscle loses its ability to accommodate, we cannot focus correctly on texts or objects that are closer to us.

Presbyopia surgery

Presbyopia or eyestrain occurs when the muscle that allows the lens to change its shape and size – called the ciliary muscle – stops working. Thanks to this movement of the lens, we are able to focus images both near and far away. When the muscle in question loses its function, we can no longer focus images correctly. To correct this defect, there are only two alternatives: the continued use of glasses, which we must continually change the prescription, or surgery, which will solve the problem definitively.
The operation takes about 10 minutes per eye and consists of replacing the crystalline lens with an intraocular lens that allows us to focus at different distances. Recovery is very quick and the following day the patient is able to see normally and with little discomfort.

What is the pre-operative period for presbyopia surgery like?

Diagnostic tests

Before surgery, the patient must undergo a series of diagnostic tests to calculate the exact power of the lens to be implanted to replace the crystalline lens. These tests are completely harmless and the patient only has to look at a light. The main drawback may be that the pupil has to be dilated in order to see the back of the eye. This will mean that for a few hours the patient may experience some glare.

How is presbyopia surgery performed?

What should I do on the day of surgery?

The procedure consists of 4 main steps:

  • ‍INCISION: A minimal incision is made (2.2mm) through which the entire operation is carried out.
  • OPENING THE CRYSTALLINE CAPSULE: Remember that the crystalline lens is made up of crystalline material and a very thin capsule that contains it. In order to fit the intraocular lens, it is necessary to empty the capsule and remove all the crystalline material. To do this, it is necessary to remove part of the capsule by making a hole in the anterior face of the crystalline lens.
  • FACOEMULSIFICATION: Through the hole we can insert a small probe that performs three functions: Emit ultrasound, aspirate and irrigate. The ultrasound helps to break up the crystalline lens masses so that they are easier to aspirate and at the same time the loss of the aspirated material must be compensated with serum so that the pressure in the eye remains constant.
  • IMPLANTATION OF THE INTRAOCULAR LENS: Once all the crystalline masses have been aspirated, the intraocular lens is implanted inside the capsule. This lens, thanks to its multifocality, has the capacity to allow us to focus at different distances, just as we did with the natural crystalline lens before it lost its focusing capacity.

As soon as the surgery is over, the patient returns to a recovery area where he or she will remain for just a few minutes and then go out on their own.

Will I feel pain during surgery?

As mentioned above, the patient is administered different types of anaesthetics as well as light sedation. This means that the patient does not suffer any pain. In any case, the patient may feel a certain sensation of pressure during the operation, but never pain.

Will I go out with a blind eye?

No. Except in exceptional cases, the patient is discharged with the eye uncovered. Although the visual quality will not be perfect, it is good enough for the patient to walk out on their own.

What is the postoperative period for presbyopia like?

What can I do and what shouldn't I do after surgery?

Immediately after the operation, an initial check-up visit is carried out to check that the lens is perfectly positioned and to make an initial assessment of the patient’s visual quality. Obviously, at this first check-up the quality will be limited, mainly because the pupil is still dilated.

The only thing the patient is not allowed to do on the day of the operation is to drive. This is because he/she is still under the effects of sedation and it would be dangerous as he/she may become drowsy.

Apart from this, the patient can practically lead a normal life, although it is advisable not to carry any weight for the first few days.

When will I start to see 100% well?

After surgery there is a period of adaptation. It should be borne in mind that the visual system has been modified and this requires a certain amount of time to get used to it. There are many factors that can vary the length of this time: initial prescription, healing capacity, age… But, in general, after about 10-15 days, vision will be practically perfect.

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